Priming with chitosan speeded lettuce’s seed sprouting

Scientists from the Russian Academy of sciences suggested a new way of seed pretreatment method to improve their germination. They demonstrated that retting of seeds in the agent on the base of chitosan—polysaccharide obtained from the shells of crustaceans, enables not only to hasten lettuce sprouting, but also to improve its yields. This approach, described in the scientific journal Molecules, will turn useful by elaboration of new ecological and economically sound technologies in vegeculture.

The quantity and quality of the yield are influenced by many factors—beginning with the quality of seed material and fertilization and ending with weather and damage of plants by varmints. Traditionally used methods of selection enable to get high-yielding cultures, resistant to varmints, but they take a lot of time. By this to increase the efficiency of growers' labour helps the simple method of pretreatment of seeds, so called priming. In fact, this is "the activation" of corcules of plants, that results in quicker and more steady seedlings. This approach enables to spend less agents than, for example, by jar method of adult plants.

"Many agricultural chemicals used for treatment of seeds can negatively influence the environment, and also are dangerous for the farm workers. In the new research we suggested to use environmentally sound agent on the base on chitosan. This polysaccharide of natural origin is non-toxic and is completely processed by soil microorganisms into safe nutrient sugars",—tells professor Valery P. Varlamov, Dr.Sci., head of Laboratory of Biopolymer Engineering of the Federal Research Centre "Fundamentals of Biotechnology" RAS.

Chitosan increases the immunity of plants and their resistibility to the environment, and also works as growth stimulator, cooperating as with proteins of cells, and also with their heritable material. The scientists from the Federal Research Centre "Fundamentals of Biotechnology" RAS used the chitosan hydrolysate from crab's shell, wherein the obtained in the reaction molecules, being small in size, can better penetrate inside the seeds and work on deep tissues. The authors of scientific research soaked the seeds of lettuce in the solution of this agent, then sprouted them and studied the characteristics of the seedlings. The experimental plants were compared with plants from seeds primed with pure water or solution of ammonium saltpeter.

Thin film created by chitosan on the surface of seeds influences the turnover between a seed and the environment. The researchers chose the dosage of the agent, that enables to reconstruct the structure of cell membranes in the process of absorption of water by seeds very carefully and to protect the seeds from the environment.

Primed with chitosan hydrolysate seeds sprouted more quickly and the plants grew more rapidly, the obtained yield was homogeneous in size, and the mass of edible part, a month after planting, was 30% higher, than required. Scientists also noticed that plants, primed with the agent, have more branchy roots system, due to which plants use the nutrients from the soil more effectively. The found effect enables to lessen the use of fertilizers and negative effects caused by unfavorable factors by growing vegetables. Salad grown with the use of agent on the base of chitosan also turned out to be more useful, because it contained the increased amount of phenol compounds that make antioxidative, anti-inflammatory and antibacterial action.

"We found the ability of chitosan to influence on various characteristics of plants, for example, the content of chlorophyll and carotenoids, level of phenolic matters and enzyme activity,—tells Tatyana Lyalina, Ph.D., research scientist of Laboratory of Biopolymer Engineering of the Federal Research Centre "Fundamentals of Biotechnology" RAS,—We also suppose that chitosan used for priming of seeds have the most significant effect on the early stages of plant growth, so in future we plan to concentrate on study of its influence on fresh sprouts".

More information:
Tatiana Lyalina et al, Effect of Seed Priming with Chitosan Hydrolysate on Lettuce (Lactuca sativa) Growth Parameters, Molecules (2023). DOI: 10.3390/molecules28041915

Provided by Russian Foundation for Basic Research